package my.util;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.Arrays;

/** 
 * 流操作工具类 
 *  
 */  
public class StreamTool {  
  
    /** 
     * @方法功能 InputStream 转为 byte 
     * @param InputStream 
     * @return 字节数组 
     * @throws Exception 
     */  
    public static byte[] inputStream2Byte(InputStream inStream)  
            throws Exception {  
        // ByteArrayOutputStream outSteam = new ByteArrayOutputStream();  
        // byte[] buffer = new byte[1024];  
        // int len = -1;  
        // while ((len = inStream.read(buffer)) != -1) {  
        // outSteam.write(buffer, 0, len);  
        // }  
        // outSteam.close();  
        // inStream.close();  
        // return outSteam.toByteArray();  
        int count = 0;  
        while (count == 0) {  
            count = inStream.available();  
        }  
        byte[] b = new byte[count];  
        inStream.read(b);  
        return b;  
    }  
  
    /** 
     * @方法功能 byte 转为 InputStream 
     * @param 字节数组 
     * @return InputStream 
     * @throws Exception 
     */  
    public static InputStream byte2InputStream(byte[] b) throws Exception {  
        InputStream is = new ByteArrayInputStream(b);  
        return is;  
    }  
  
    /** 
     * @功能 短整型与字节的转换 
     * @param 短整型 
     * @return 两位的字节数组 
     */  
    public static byte[] shortToByte(short number) {  
        int temp = number;  
        byte[] b = new byte[2];  
        for (int i = 0; i < b.length; i++) {  
            b[i] = new Integer(temp & 0xff).byteValue();// 将最低位保存在最低位  
            temp = temp >> 8; // 向右移8位  
        }  
        return b;  
    }  
  
    /** 
     * @功能 字节的转换与短整型 
     * @param 两位的字节数组 
     * @return 短整型 
     */  
    public static short byteToShort(byte[] b) {  
        short s = 0;  
        short s0 = (short) (b[0] & 0xff);// 最低位  
        short s1 = (short) (b[1] & 0xff);  
        s1 <<= 8;  
        s = (short) (s0 | s1);  
        return s;  
    }  
  
    /** 
     * @方法功能 整型与字节数组的转换 
     * @param 整型 
     * @return 四位的字节数组 
     */  
    public static byte[] intToByte(int i) {  
        byte[] bt = new byte[4];  
        bt[0] = (byte) (0xff & i);  
        bt[1] = (byte) ((0xff00 & i) >> 8);  
        bt[2] = (byte) ((0xff0000 & i) >> 16);  
        bt[3] = (byte) ((0xff000000 & i) >> 24);  
        return bt;  
    }  
  
    /** 
     * @方法功能 字节数组和整型的转换 
     * @param 字节数组 
     * @return 整型 
     */  
    public static int bytesToInt(byte[] bytes) {  
        int num = bytes[0] & 0xFF;  
        num |= ((bytes[1] << 8) & 0xFF00);  
        num |= ((bytes[2] << 16) & 0xFF0000);  
        num |= ((bytes[3] << 24) & 0xFF000000);  
        return num;  
    }  
  
    /** 
     * @方法功能 字节数组和长整型的转换 
     * @param 字节数组 
     * @return 长整型 
     */  
    public static byte[] longToByte(long number) {  
        long temp = number;  
        byte[] b = new byte[8];  
        for (int i = 0; i < b.length; i++) {  
            b[i] = new Long(temp & 0xff).byteValue();  
            // 将最低位保存在最低位  
            temp = temp >> 8;  
            // 向右移8位  
        }  
        return b;  
    }  
  
    /** 
     * @方法功能 字节数组和长整型的转换 
     * @param 字节数组 
     * @return 长整型 
     */  
    public static long byteToLong(byte[] b) {  
        long s = 0;  
        long s0 = b[0] & 0xff;// 最低位  
        long s1 = b[1] & 0xff;  
        long s2 = b[2] & 0xff;  
        long s3 = b[3] & 0xff;  
        long s4 = b[4] & 0xff;// 最低位  
        long s5 = b[5] & 0xff;  
        long s6 = b[6] & 0xff;  
        long s7 = b[7] & 0xff; // s0不变  
        s1 <<= 8;  
        s2 <<= 16;  
        s3 <<= 24;  
        s4 <<= 8 * 4;  
        s5 <<= 8 * 5;  
        s6 <<= 8 * 6;  
        s7 <<= 8 * 7;  
        s = s0 | s1 | s2 | s3 | s4 | s5 | s6 | s7;  
        return s;  
    }  
    
    /** 
     * 二进制字符串转byte 
     */  
    public static byte decodeBinaryString(String byteStr) {  
        int re, len;  
        if (null == byteStr) {  
            return 0;  
        }  
        len = byteStr.length();  
        if (len != 4 && len != 8) {  
            return 0;  
        }  
        if (len == 8) {// 8 bit处理  
            if (byteStr.charAt(0) == '0') {// 正数  
                re = Integer.parseInt(byteStr, 2);  
            } else {// 负数  
                re = Integer.parseInt(byteStr, 2) - 256;  
            }  
        } else {// 4 bit处理  
            re = Integer.parseInt(byteStr, 2);  
        }  
        return (byte) re;  
    }  
    
    /** 
     * 将byte转换为一个长度为8的byte数组，数组每个值代表bit 
     */  
    public static byte[] getBooleanArray(byte b) {  
        byte[] array = new byte[8];  
        for (int i = 7; i >= 0; i--) {  
            array[i] = (byte)(b & 1);  
            b = (byte) (b >> 1);  
        }  
        return array;  
    }  
    /** 
     * 把byte转为字符串的bit 
     */  
    public static String byteToBit(byte b) {  
        return ""  
                + (byte) ((b >> 7) & 0x1) + (byte) ((b >> 6) & 0x1)  
                + (byte) ((b >> 5) & 0x1) + (byte) ((b >> 4) & 0x1)  
                + (byte) ((b >> 3) & 0x1) + (byte) ((b >> 2) & 0x1)  
                + (byte) ((b >> 1) & 0x1) + (byte) ((b >> 0) & 0x1);  
    }  
    public static void main(String[] args) {  
        byte b = 0x35; // 0011 0101  
        // 输出 [0, 0, 1, 1, 0, 1, 0, 1]  
        System.out.println(Arrays.toString(getBooleanArray(b)));  
        // 输出 00110101  
        System.out.println(byteToBit(b));  
        // JDK自带的方法，会忽略前面的 0  
        System.out.println(Integer.toBinaryString(0x35));  
    }
}  